Alpha phase nucleation during isothermal aging heat treatments in Ti-Nb and Ti-Nb-Sn alloys

• Grant number: 12/10164-8
• Support type: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2012
• Effective date (End): January 31, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal researcher: Rubens Caram Junior
• Grantee: Camilo Augusto Fernandes Salvador
• Home Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 13/23532-8 - Effects of aging heat treatments on phase precipitation and mechanical behavior of Ti-30Nb-xSn beta metastable titanium alloys, BE.EP.MS

Abstract

This research deals with the study of phase transformations in metastable beta titanium alloys during aging heat treatments. The high microstructure instability of metastable beta titanium alloys has limited their industrial applications for years. Recently, improvements in knowledge of physical metallurgy of these alloys led to commercial use of them, particularly in aerospace and medical industries. However, aspects related to metastable phase precipitation, such as the precipitation of orthorhombic martensite during aging heat treatments are poorly understood. In the present work, alloys in the Ti-Nb and Ti-Nb-Sn systems will be prepared in arc furnace under controlled atmosphere, homogenized at high temperatures and plastically deformed. Following, such samples will be solution heat treated in the beta field, rapidly cooled to room temperature and aged at different conditions of temperature and time of heat treatment. The objective is to verify orthorhombic phase precipitation. Samples will be analyzed by microscopy, differential scanning calorimetry, X-ray diffraction at high temperatures, microhardness and nanohardness. At the end of this work it is expected to gain knowledge that helps to understand mechanisms of phase transformation in titanium alloys, which will allow the optimization of titanium alloys applied industrially.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SALVADOR, C. A. F.; OPINI, V. C.; LOPES, E. S. N.; CARAM, R. Microstructure evolution of Ti-30Nb-(4Sn) alloys during classical and step-quench aging heat treatments. MATERIALS SCIENCE AND TECHNOLOGY, v. 33, n. 4, p. 400-407, 2017. Web of Science Citations: 4.

SALVADOR, CAMILO A. F.; LOPES, EDER S. N.; OSPINA, CARLOS A.; CARAM, RUBENS. Orthorhombic martensite formation upon aging in a Ti-30Nb-4Sn alloy. Materials Chemistry and Physics, v. 183, p. 238-246, NOV 1 2016. Web of Science Citations: 5.